1. Field of the Invention
This invention relates to a hybrid type inflator having a structure that an interior part of a housing is charged with a pressurized gas and a gas generating agent capable of generating a gas when combusted.
2. Related Art
A hybrid type inflator has heretofore been used for expanding an air bag in an air bag device, wherein the air bag is expanded by allowing a combustion gas generated by combustion of a gas generating agent and a pressurized gas to flow into the air bag when actuated. In such conventional inflator, a mixture gas obtained by mixing oxygen and an inert gas is used as the pressurized gas, and a gas in which a quantity of heat to be generated during combustion is set to about 5000 J/g has been used as the gas generating agent (see JP-A-8-282427, for example).
Generally, in the hybrid type inflator, a combustion residue (mist) of the gas generating agent is generated simultaneously with the generation of the combustion gas due to the combustion of the gas generating agent at the time of actuation, and such mist is discharged to the outside of the inflator from a gas discharge opening of the inflator together with the expanding gas formed of the pressurized gas and the combustion gas. Since the flowage of the mist into the air bag is undesirable, it is preferable to suppress the generation of the mist as small as possible. Also, the inflator of the air bag device mounted on vehicles generally has a high output in order to ensure an occupant protection function, and it is desirable to suppress a weight and a size as small as possible from the viewpoint of achievement of a lighter weight of the vehicle itself and from the viewpoint of improvement in degree of freedom of placement position.